Thanks for the reply Gareth.
I actually managed to re subscribe successfully last night, but not via the website.
I logged into the Netflix app on my STB and it was asking me to restart my subscription but notice the option for amending my payment details. From there I found an option of paying via my Virgimedia account. I selected that and restarted my subscription. Because I had an ultimate subscription, I’m waiting to see on my bill that I am only charged the difference between the standard and ultimate.
many thanks for the reply though.